Most of the sex dating sites are scams.
Hate to tell you this but you're gonna have to get a woman the hard way. ie sending e-mails, talking on the phone, going out on dates etc.
Try Soulmates from the Guardian. I haven't met my ideal girl yet, but i've been on quite a few nice dates.
Remember, women don't advertise on dating sites for sex. If they want sex they just go out to their local pub or club and pull.
You have been warned!!!!
Good luck.
Peace.